Acute Toxicity Assessment of Reactive Red 120 to Certain Aquatic Organisms.

Laboratory experiments were conducted to evaluate the acute toxicity of a widely used textile dye namely Reactive Red 120 (RR 120) on certain aquatic species such as Pseudokirchneriella subcapitata (green alga), Lemna gibba (duck weed), Daphnia magna (water flea) and Oncorhynchus mykiss (Rainbow trout). All experiments were performed as per the OECD Guidelines for Testing of Chemicals. The toxicity end points of EC50, LC50, NOEC and LOEC for RR 120 were determined with 95% confidence limits using TOX STAT version 3.5. The EC50 of RR 120 for green alga, duck weed and water flea are >100.00, 64.34, 10.40 mg L(-1), respectively and LC50 for Rainbow trout is 78.84 mg L(-1). Based on the results, the test item RR 120 could be classified as non-toxic to green alga, harmful to duck weed and Rainbow trout, toxic to water flea.

Toxicity Assessment of Expired Pesticides to Green Algae Pseudokirchneriella subcapitata.

In order to investigate the effect of expired pesticides on the yield and growth rate of green algae Pseudokirchneriella subcapitata, a study was conducted as per the Organisation for Economic Cooperation and Development (OECD) guideline number 201. Fifteen expired pesticide formulations, most commonly used in Indian agriculture, were tested in comparison with their unexpired counterparts. The expired pesticide formulations studied belonged to various class and functional groups: organophosphate, pyrethroid-based insecticides; azole-based fungicides; acetamide, propionate, acetic acid-based herbicides; fungicides mixtures containing two actives-azole and dithiocarbamate. The toxicity endpoints of yield (EyC50: 0-72 h) and growth rate (ErC50: 0-72 h) of Pseudokirchneriella subcapitata for each pesticide formulation (both expired and unexpired pesticides) were determined statistically using TOXSTAT 3.5 version software. The results pointed out that some expired pesticide formulations exhibited higher toxicity to tested algal species, as compared to the corresponding unexpired pesticides. These data thus stress the need for greater care to dispose expired pesticides to water bodies, to avoid the effects on aquatic ecospecies tested.